Not in my opinion.
I added them after then had been in another tank about a year, but I had no formal QT for them, it just happened that I didn't use them until about a year after I got them.2 - How do you quarantine them, if at all?
I use a few assassin snails to keep the population in check.3 - How do you control their population growth? Does it ever get out of hand?
Not at all, especially for sand substrate.4 - Do you regret getting them?
Nope.5 - Do they eat plants?
HTHs,
-jim